Seam welding machine for pipes



April 1953 H. B. TROMBLEY SEAM WELDING MACHINE FOR PiPES 4 Sheets-Sheet1 Filed April 5, 1951 ATTORNEY w RY? &

INVENTOR P 7, 1953 H. B. TROMBLEY SEAM WELDING MACHINE FOR PIPES 4Sheets-Sheet 3 Filed April 5, 1951 ATTORNEY i April 7, 1953 H. B.TROMBLEY 2,634,354 SEAM WELDING MACHINE FOR PIPES Filed April 5, 1951 4Sheets-Sheet 4 INVENTOR.

19 9 71 0 Womb/ea. BY fa I WW ATTORNEY Patented Apr. 7, 1953 SEAMWELDING MACHINE FOR PIPES Henry B. Trombley, Bay City, Mich., assignorto The Michigan Pipe (10., Bay City, Mich.

Application April 5, 1951, Serial No. 219,329

7 Claims.

The present invention relates to scam welding machines, and moreparticularly to a welding machine for welding the seam of pre-formedpipe, conduits and other workpieces of cylindrically formed metalblanks.

One object is to provide a seam welding machine for welding the endedges of cylindrically bent and pie-formed metallic sheets to produce ametallic pipe having a single longitudinal seam welded joint.

Another object is to provide a seam welding machine for pipes and thelike in which the pipe blank is held in position with its end edges inabutting relation throughout the entire length of the seam so that thewelding head can be bodily moved longitudinally of the pipe for weldingthe seam without causing undue stresses or strains to be set up in thepipe during the welding operation.

Another object is to provide a welding machine in which a pro-formedpipe blank of sheet metal bent cylindrically and tack welded at spacedintervals along the end edges of the metal sheet is properly held inposition by means of a series of clamping fingers which clampinglyengage the end edges of the blank on each side of the seam with evenpressure throughout the entire length of the seam such that the endedges of the pre-formed blank will be properly spaced for the receptionand deposition of the weld metal introduced to the seam.

Another object is to provide a seam welding machine for holding apre-formed cylindrical blank in proper position throughout the entirelength of the seam by a series of equidistantly spaced gripping fingersin frictional engagement with the ends of the cylindrical blank alongthe seam, and on each side thereof, to insure a more even distributionof the weld metal and to produce a welded seam of uniform dimensions.

Another object is to provide a seam welding machine for pipe in whichthe pre-formed cy1indrical pipe blank is removably supported on areleasable platen and anvil arranged to facilitate the easy loading ofthe pipe blanks for welding, and the quick removal of the pipe afterbeing welded.

Another object is to provide a pipe seam welding machine having anadjustable platform which is arranged to be adjusted vertically inparallelism, with the axis of the pipe blank and the anvil and platen intrue parallel relation. The platform being arranged to exert an upwardpressure force on the pipe blank in such a manher that the blank isslightly distorted so that after the seam is welded, the pipe willassume a true cylindrical shape.

Another object is to provide a seam welding machine in which thegripping fingers are moved into contactual engagement with the end edgesof the pro-formed cylindrical pipe blank by fluid pressure means,arranged to exert a uniform pressure force on each of the grippingfingers throughout the entire length of the pipe seam, whereby the endedges of the pipe seam Will be held in true abutting relation, and inclamping engagement with the platen on the releasable anvil.

Another object is to provide a welding machine in which the releasableanvil is provided at one end with a clamping device, which can bequickly and easily operated to facilitate the quick and easy insertionand removal of pipe blanks.

Another object is to provide a welding machine having an adjustableplatform for the pipe blank which is operated by pressure fiuid means toproperly position the pipe blank at the desired level, and exert a forceon the blank at a diametral point opposite the gripping fingers.

Another object is to provide a welding machine of the above-mentionedtype with gravity biased means for urging the gripping fingers out ofengagement, with the end edges of the pipe seam, to hold the same in aninoperative position when loading and unloading pipe blanks in thewelding machine.

Another object is to provide a pipe seam welding machine having manualcontrol means for manipulating the gripping fingers to insure properpositioning thereof, when loading pipe blanks in the welding machine.

Another object is to provide a pipe seam welding machine in which theseries of clamping fingers are urged into frictional clampingengagement, with the end edges of the pipe blank, by inflatable tubesarranged such as to exert uniform pressure on each of the grippingfingers, with the result that the ends of the pipe blank are uniformlyheld against the platen throughout the entire length of the seam.

Another object is to provide a welding machine fcr effecting a weldedjoint between the end edges of a cylindrically bent blank, in which theblank is held in a fixed position and the welding unit is mounted totraverse the seam and move longitudinally with the axis or" the pipe.

Another object is to provide a seam Welding machine in which the weldingunit is bodily movable longitudinally with respect to the pipe seam,

and is manually operated so that various portions of the pipe seam canbe welded to form a continuous welded joint.

Another object is to provide a seam welding machine for pipe havingaprons arranged on each side of the pipe to collect slag and the like,dropping from the seam during the welding thereof.

Other objects and advantages of the invention will become apparentduring the course of the following description of the accompanyingdrawings. wherein:

Figure l is a side elevational view of the seam welding machine, showingthe adjustable platform in an elevated position and the releasable anvilheld in its operative position.

Figure 2 is an end elevational view of the seam welding machine,illustrating the manner in which the anvil is released to receive apreformed pipe of cylindrical section, and showing the gripping fingersin their inoperative position.

Figure 3 is an end elevational view of the opposite end of the weldingmachine, showing the manually controlled and gravity biased linkagesystem for controlling the series of gripping fingers which engage theends of the cylindrically formed blank, and showing the manner in whichthe releasable anvil is supported on the frame.

Figure 4 is a fragmentary side elevational view illustrating the anviland the manner in which the clamping device is released in dotted linesto permit the anvil to be lowered when loading and unloading pipe blanksthereon, likewise shown in dotted lines.

Figure 5 is a horizontal cross-sectional view taken on irregular lines5-5 of Figure 1, and looking in the direction of the arrows, toillustrate the series of gripping fingers and the manual control meansfor manipulating the same when loading and unloading pipe blanks, andcompleted pipes.

Figure 6 is a side elevational view of the adjustable platform, showingthe operating linkage therefor, and illustrating the platform in itslowermost position.

Figure '7 is an enlarged cross-sectional view taken on line 'll ofFigure 1, and looking in the direction of the arrows, to illustrate themanner in which a pipe blank is supported on the platform and anvil withthe side edges or complementary ends presented to the gripping fingers,which are shown as being held in an inoperative position by the gravity'biased linkage such as when loading a pipe blank onto the anvil.

Figure 8 is an enlarged cross-sectional view taken on line 88 of Figurel and looking in the direction of the arrows, to illustrate the mannerin which a pipe blank is supported on the platform with its edges heldin position by the gripping fingers which are actuated by the inflatabletubes which are inflated by a pressure fluid connected to a suitablesource or supply, and

Figure 9 is a perspective view of the releasable clamp for engaging andholding one end of the anvil in its operative position.

In the drawings, and more in detail, there is shown for the purpose ofconvenience of illustration a welding machine for welding the seam of acylindrically bent blank sheet prepared by tack welding at a few placesto hold the same with the ends of the metal sheet in its cylindricalform prior to the continuous welding operation, to produce a welded seamwhich will be both airand liquidtight. I v

Generally, the welding machine comprises a frame structure 5 having anadjustable vertically movable pipe blank supporting platform structureE, a releasable anvil I for receiving the pipe blank and holding thesame in position for being clamped by clamping members 8. A weldingunit, likewise generally designated 9, is movable to and fro along theframe 5 with respect to the pipe blank to weld a continuous seam andjoin the abutting edges of the cylindrically bent or pre-formed blankwhich has been prepared by tack welding the seam at a few spaced apartlocations, such as at the ends of the blank.

The frame structure 5 includes side frame members it of angle section,which are connected at their ends by transverse frame bars H, likewiseof angle section, suitably held in place by welding or the like. Thefram members Iii and ii are supported above the floor surface ontransverse blocks [2 and secured within the corners of the frame membersIt and i I are upright frame members it and Hi of channel section. Theuprights I3 and M- are secured in place by welding or the like, asbefore, and are connected together adjacent their upper ends by sideframe members l5 and end frame members iil.

Adjacent the right hand end of th machine, Figure l, at each sidethereof, is an upright 19 of channel section which has its lower endaffixed to the side frame member It, and its upper end connected to theside frame member l5 at each side of the machine, and side brace members2t extend between the uprights hi and it to add rigidity.

Mounted centrally of the fabricated frame structure 5 is a pipesupporting platform structure 6, which includes a channel-shaped base 21having its opposed flanges 22 extending upright. A pair of metal strips23 are secured to the channel beam 2| in spaced apart relation andadjacent the opposed flanges 22 to form therebetween a guideway forreceiving a guide block 25 of H section. Formed on the upper portion ofthe guide block 2 5 is a head 25 having an opening 25 for receiving alongitudinal control rod 2?. The opposite end of the base 2! is providedwith a similar block 28 which is rigidly secured in position, and isprovided with a head having an opening in alinement with the opening 26,for receiving the control rod 2?, and said head is designated by thereference character 29. The control rod 27 is connected to the pistonrod 3 3 of a control cylinder 3! which is anchored between the opposedflanges 22 of the base 25, and a suitable coupling 32 is provided foradjustably coupling the control rod 2'! and the piston rod 38. Pressurefluid supply pipes 33 and 3d are connected to a suitable pressure sourcesuch as the air reservoir of a compressor pump, and suitable valves areinterposed for controlling the admission of air under pressure toopposite sides of the cylinder 3|. A pin (not shown) is provided forconnecting the control rod 2? to the slidable guide block 2% and extendsthrough the head 25 thereof. Thus, when the piston rod 39 isreciprocated to and fro the guide block 25 will be correspondinglymoved.

The ad ustable platform includes a plate 35 which is disposed beneaththe anvil l, and said plate is provided with a channel bar 36 on itsunderside, having its opposed flanges 37 extending downwardly. Theplatform 35 is connected to the blocks 25 and 29 by compound links 3t39and 513- arranged in pairs. The compound links 39 have their lower endspivotally connected to the head of the guide block by pins 43 whichproject laterally from the head 25, and are supported on the upper edgesof the opposed flanges 22 of the base 2!. The other ends of the pair oflinks 39 are connected to the opposite end of the channel bar 36 bymeans of a pin it which extends through the flanges 31 in suitableopenings therein, and projects a slight distance laterally therefrom.

Similarly, the levers 4| have their lower ends connected to the head 29of the block 23 by means of a pin 35, while the upper end of the link 4!is connected to the opposite end of the platform 6 and to the opposedflanges 37 of the channel beam by means of a transverse pin 46 (Figure8). The links 33 and are pivoted to the heads 25 and 29 of the blocks 24and 28 respectively, while their other ends are pivoted to the levers 39and 49. The pair of levers 38 being pivoted to the levers 4! as at 4'1,and similarly the pair of levers 45 are pivoted to the pair of levers 39as at 48. It will thus be seen, that when pressure fluid is admitted tothe left hand end of the cylinder 3| through the pipe 33, the slideblock 24 will move to the right and the platform .35 will be elevated toraise a pipe blank into proper position so that the seam will bepresented to the welding unit.

Coil springs are mounted on the block 25 and 29 and are arranged toengage the underside of the platform 35, to absorb shocks when theplatform is lowered. The linkage system is similar to a toggle leverstructure and permits the vertical adjustment of the platform 35 in trueparallel relation relative to the gripping finger structure 8 and anvill.

Mounted above the adjustable platform structure 6 is a releasable anvilwhich is formed of a pair of angle bars 5| arranged in face to facerelation, with their flanges 52 extending in opposed relation. The anglebars 51 are connected by welding or the like, and a platen bar 53 issupported and secured to the opposed flanges 52 likewise by welding. Theplaten bar 53 is provided with a transversely curved surface of a shapeto conform to the contour of the inner periphery of a pipe blank (Figs.7 and S) One end of the anvil l is movably and rockably supportedbetween a pair of angle bars 5 which are secured to a transverse framemember 55 extending between the uprights it at the right hand end of themachine. The opposed flanges 55 of the angle bars E l are spaced asufficient distance to receive the angle bars 5i, and hold the anvil lin position.

The opposite end of the anvil 'l is releasably supported on theintermediate transverse frame bar it at the left hand end of themachine, and the clamping lever 5? is provided for this purpose and issuppo ted at its upper end between the flanges 58 of a pair of bracketplates 59 secured to the transverse frame bar !6 by bolts or otherthreaded fasteners Bil. The clamping bar 57 has its upper end enlargedand provided with an opening 64 (Figure 9) for receiving a pivot pin 62,and the lower end is provided with a ring-shaped bearing 63 forreceiving a rotatable disk 64. A clamping pin 65 extends through aneccentric opening 66 in the disk 54 and i rigidly secured to the disk torotate therewith. The ends of the clamping lever 65 are provided witheyes 5'! for receivin a handle or actuator d8 of L -shaped constructionhaving its leg portions 6d slidably received in the eyes El. The freeends of the leg portions 89 may be enlarged to permit the slid- 6 ingmovement of the handle actuator 68 without the same becoming displacedfrom the openings of the eyes 61.

The left hand end of the anvil 1 formed by the angle bars 5| is providedwith a pair of spaced projections 1B which are affixed to opposite sidesof the anvil l, and project longitudinally from the end of the anvil forremovably receiving the pivoted rod 5?. The clamping rod 65 being arranged to engage the lower edges of the extensions 10 (Fig. 2), so thatwhen the handle actuator 68 is swung upwardly from its lowermostposition the clamping bar 65 will rotate eccentrically with respect tothe ring bearing 6-3 and will cause the left hand end of the anvil to bemoved upwardly to its operative position.

Mounted above the anvil l and extending longitudinally of the frame is apair of spaced apart beams 13, which have their ends connected to andsupported by one of the transverse frame bars l6, and a transverse bar14 extending between the frame uprights it. The beams 13 may be Weldedor otherwise secured in place, and are provided with angle bars 75 whichhave their flanges l6 arranged in opposed relation as clearly shown inFigures 7 and 8. Secured to the underside of the opposed flanges T6 is apair of angle bars 78 which have their flanges 16 arranged in spacedapart opposed relation and welded or otherwise secured to the underfaces of the opposed flanges 15 of the angle bars l5.

Formed adjacent each end of the angle bars 18 are correspondinglypositioned lugs 80 and 8! for supporting a pair of parallel rods 82 inalined opening in the respective lugs 80BI. Secured to each of the rods32 and extendin between the lugs Bil-8i is a plate 83 arranged one oneither side of the anvil 7 to swing vertically about the pivot axis ofthe rods 82. Secured to the pivoted plates 83 and projecting from theouter ends thereof, is a series of gripping fingers 85 which areinwardly and downwardly bent in a direction toward the platen 53. Thegripping fingers 85 are welded or otherwise secur d in equidistantlyspaced apart relation on the upper surfaces of the pivoted plates 33,and the lower ends thereof are arranged in spaced apart relation toprovide a pathway therebetween for the welding electrode.

Mounted above each of the pivoted plates 83 is an inflatable tube 86which extends the entire length of the plates 83, and has one endclosed, while the other end as at 81 is provided with a coupling nipple38 to which is attached a supply pipe 89. The supply pipe 89 of eachtube 88 extends through openings in a bracket plate 953 secured to theenlarged opposed flanges EH of the anvil I, the flanges 9! being anenlarged continuation of the flanges 52 for supporting the angle bracket9i]. A supply pipe 533 is connected to the coupling, 88, and has itsother end connected to a suitable air pressure source having controlvalves (not shown) to admit air pressure to the spaced apart tubes 86and thus urge the pivoted plates 83 and gripping fingers 85 downwardlyto clamp-ingly engage a pipe P on each side of the pipe seam.

In order to hold the pair of pivoted clamping plates 83' and theirfingers 85 in an elevated position while loading or unloading pip blanksand pipe after being welded, there is provided a gravity biased linkagesystem supported on the frame and adapted to normally hold the clampingplates $3 in an elevated position when the rubber tubes 86 are deflated.This structure comprises a transverse shaft I00 having its endssupported in suitable journal bearings IUI at each side of the machine,and supported on the flanges of the side frame members ill. With one endof the shaft IO!) extending through an opening in the angle bar It! atone side of the machine for receiving the hub :02 of a hand lever I93.Secured to the intermediate portion of the shaft Hill is a pair oflevers I84 which have their upper ends angularly bent as at 185 (Figurefor providing closely spaced free end portions I963. The end portionsare provided with longitudinal slots for receiving a pin IUI havingheads 38 at each end thereof slightly larger than the slot to preventdisplacement of the pin. A roller IE9 is mounted on the pin Iiil, andsupported on the pin IE1 is a rectangular frame Iii) (Fig. 3) which hasvertical side legs disposed between the roller H39 and the arms I86 ofthe levers iil i.

Supported on the rectangular bracket IIG' is an adjustable weight I Iwhich is suspended from the bracket by means of a rod i I2 which has anenlarged upper end secured to the bracket HQ, while the lower end may beprovided with a threaded portion for receiving a retaining nut (notshown) Also mounted on the machine frame 5 and between the uprights I9 ia shaft H3 to which is pivoted a lever I I4, which has one end extendingbeneath the roller Hi9, while its opposite end is disposed beneath oneend of the pair of clamping plates 83. Formed on the end of the leverIIG opposite the end engaged by the roller M39, is a bearing boss H5(Figure 7) which provides a bearing for a, transverse pin I36 havingheads ill at each end thereof. Pivotally connected to the pin H6 is apair of parallel levers [IE which extend upwardly at one end of theivoted plates 83 and are pivotally connected to the outer ends of theplates by means of pivot pins as at 4 I9. The anvil I has its opposedflanges 52 notched as at I28 to accommodate the actuatnig rods IIB forthe clamping plates 83.

It will be seen, that the adjustable weight III will normally urge theclamping plates 83 upwardly when the rubber tubes 83 are deflated asshown in Figure 7, and that by manipulating the hand lever I03 at oneside of the machine the clamping plates 83 may be manually adjusted whenpositioning pipe blanks of cylindrical shape for welding. That is tosay, that the clamping plates 83 and their clamping fingers 85 may beadjusted while positioning the seam of a pipe blank on the anvil I, andprior to the inflation of the tubes 35 to properly aline the seam of thepi e for presentation to the welding electrode.

The welding unit 8 is of conventional construction and includes aplatform I2I having electrical control mechanism I22, and an upstandingbracket plate I26 for supporting a reel shaft I25 on which is mounted areel I28. The welding unit 9 is supported on a pair of channel beams I2?which are arranged in opposed relation secured in place by welding orthe like, and said channel beams are supported between the uprights I3and M on brackets I29 and I39 respectively. The bracket I23 is suspendedand also supported from the cross beam I6 at one end of the machine bysuspension rods I3I which have their lower ends threaded for receivingthreaded fasteners to secure the plate I29 in position. One end of theplate I29 may be welded or otherwise affixed to the upright I3. Theother bracket plate I38 is formed with an angle portion 133 which iswelded to the upright I l on the corresponding side of the machine.

A track plate I31; is welded to one of the channel beams I2? and has theupper edge thereof projecting beyond the channel beams to provide aguide trackway for a roller I35 supported on the platform IZI by meansof a bracket I36 afiixed to the platform I2I in any suitable manner.

Formed integral with the platform is a depending bracket plate I33 whichis provided with an arm I39 for rotatably supporting a roller I583 (Fig.3). The roller Ifi engages the opposed face of one of the channel beamsI2? to movably support the welding unit 9 for sliding movementlongitudinally of the frame 5. It being understood that supportingrollers I46 are mounted at each end of the platform I2 1, while a singleroller is mounted on the opposite side of the platform I2 I.

Supported on the depending bracket plate I38 is a flux box #52 forcontaining a quantity of welding flux to produce a slag and inert gas atthe welding point as usual. Wound on the drum I25 is a welding electrodeM3 which passes through the flux box Hi2 so that a coating of flux willbe extruded on the welding electrode I 33, before the same is presentedto the seam to be welded. The electrode M3 is automatically fed to theseam by conventional mechanism, and the end of the electrode is adaptedto first contact the metal to initiate the arc, and is thenautomatically raised a slight distance for traversing the seam. Theelectrical connections with the electrode and anvil of the weldingmachine are not shown, since they are conventional in electric arcwelding. The extruding nozzle I50 is mounted on the lower end of theflux box M2, and is provided with a central opening of an enlargeddiameter and greater than the diameter of the electrode to provide arelatively heavy flux coating on the electrode as it is fed forwardlyduring the welding operation.

In order to catch excessive flux and slag during Welding canvas apronsare connected to each side of the supporting platform 35 by beinginterposed between the under surface of the platform 35 and a clampingbar I56 secured in place by suitable fastening elements (not shown). Theouter edges of the canvas aprons I55 are supported by clips I5? attachedto the frame structure at suitable locations, and preferably between theuprights i3 and E9. The canvas aprons !55 are provided with strips 158secured along their outer edges which are received in the clips I 57 atthe ends thereof. Thus, the rods I58 may be lifted vertically todisplace the same from the clips I51 and permit the removal of theaccumulation of excessive flux and slag deposited on the aprons I55.

The extruding nozzle 158 is presented and extends downwardly between theangle beams ?5 so that the electrode I43 may be fed to the seam of thepipe P between the frictional gripping and clamping fingers 85.

In operation, a pipe blank is formed from a sheet of rectangular metalof a length corresponding to the length of pipe desired. The rectangularmetal sheet is bent or preformed to cylindrical shape with the ends ofthe cylindrically bent sheet in closely spaced relation. The pipe blankthus formed may be prepared by tack welding the ends of the seam priorto installation or loading in the welding machine or if desired, thiscan be accomplished in the machine itself. After the pipe blank is thusformed to substantially true cylindrical shape, it is loaded into thewelding machine by releasing the clamping bar El by swinging the handle68 downwardly from the position shown in Figure 1 to the position shownin Figure 2. This permits the bar 65 to drop downwardly by reason of thefact that the bar is secured to the eccentric 64, and permits the bar 65to move downwardly out of engagement with the spaced apart projectingplates 'lil aillxed to one end of the anvil I on each side thereof. Bythen swinging the clamping bar 5? about the pivot pin 82 in a directionoutwardly, the anvil "i will drop downwardly at one end as shown indotted lines in Figure 4.

The pipe blank can then be slipped longitudinally over the anvil l withthe seam resting upon the platen 53. After the pipe blank P has beenpositioned on the anvil i, the handle 58 is swung inwardly and upwardlyto lock the free swinging end of the anvil in position. When the handleE8 is swung upwardly over the ends of the projecting bars Hi, the anvilwill be securely held in place. It being understood, that the rubbertubes 85 are deflated and that the clamping fingers 85 are held in anelevated position by the gravity biased lever i M. After the pipe blankP has been placed on the anvil the hand lever "33 can be moved to theleft (Figure 5) so as to permit the clamping plates 83 and grippingfingers 85 to move downwardly into engagement with the ends of thecircularly bent sheet to properly position the seam and center the samewith respect to the welding electrode I43. After the clamping fingers 35have been properly positioned with respect to the seam, pressure fluidor air under pressure is admitted to the pipes 3H and 93 to elevate theplatform 35 against the underside of the pipe and inflate the rubbertubes 86 so as to cause the gripping fingers 85 to frictionally andtightly engage the metal at each side of the seam and press the sameinto engagement with the curved surface of the platen 53. The platform35 urges the pipe upwardly with sufficient pressure to hold the meetingedges in close relation and in true circular registration.

The welding electrode [43 is then lowered automatically into engagementwith the seam of the pipe P to strike an arc and is likewiseautomatically raised a slight distance after the arc has been struck.The welding unit 9 is then moved along the trackway [21 to form acontinuous welded seam for the meeting edges of the pipe P.

The flux extruded on the electrode cable M3 is consumed less rapidlythan the metal of the electrode which serves to concentrate the arc andshield the rubber tubes 86 against excessive heat.

Similarly, the gas generated by the flux concentrates the heat in thearea of the seam and prevents the pivoted plates 33 and rubber tubes 85from becoming damaged. Excess flux and slag formation falling away fromthe seam on both sides of the pipe are caught by the aprons I55 andaccumulates as at 160.

After the pipe seam has been welded by manually moving the welding unit9 to and fro along the guide traclrway 82?, the tubes 86 are deflatedand the hand lever W3 is shifted so that the weight Hi will urge theclamping plates 33 and gripping fingers 35 upwardly and out ofengagement with he metal at each side of the welded seam. Similarly, thecontrol valves for the cylinder 35' are manipulated to permit theplatform 35 to be lowered. Next, the clamping lever 5! is released aspreviously described to allow the anvil "l to drop downwardly so thatthe completed or seam welded pipe can be removed from the 10 anvil bybeing slid longitudinally therefrom at one end of the machine.

In the event that the pre-formed pipe P is tack welded in the machine,the operation is similar to that previously described and the grippingfingers are manipulated by operation of the hand lever Hi3 until thejoining ends of the pipe have been properly positioned in longitudinalalinement with the center of the platen 53. After the pipe blank hasbeen properly positioned, it can be tack welded at the ends and thencontinuously welded along the seam to prevent distortion created byexcessive heat. In accordance with accepted welding practice thecontinuous seam may be accomplished by welding centrally andworkingtoward each end, and since the welding unit 9 is manuallycontrolled, this can be easily facilitated.

After the pipe seam has been continuously welded, the completed pipe Pcan be removed and subjected to heat treating processes if desired toremove stresses and strains created by the welding heat, and thefinished pipe product can be employed for various purposes as a conduitfor liquids or the like which is completely leakproof.

it is to be understood, that the form of the invention herewith shownand described is to be taken as a preferred embodiment and that variouschanges in the shape, size and arrangement of parts may be resorted towithout departing from the spirit of the invention or the scope of thesubjoined claims.

I claim:

1. In a seam welding machine, an elongated trackway, a welding unitmovably mounted on said trackway, an anvil mounted beneath said weldingunit for supporting a cylindrical pipe blank with its seam presented tosaid welding unit, a vertically adjustable platform beneath said anviland a handle on said machine to support one end of said anvil and holdthe same in its operative position, said handle being eccentricallypivotal on said machine to lower said end of the anvil and swingable outof engagement therewith to allow the loading and unloading of said pipeblank.

2. In a seam welding machine, a trackway, an electric welding unitmovable to and fro along said trackway, an anvil positioned beneath saidwelding unit for receiving a pipe blank to be welded with the pipe seampresented to the welding unit means on one end of said machinesupporting one end of said anvil to allow limited swinging movementthereof in a vertical plane, a lever pivotally mounted on the oppositeend of said machine to swing in a vertical plane, a handle eccentricallymounted on said lever to normally support the opposite end of the anviland swingable downwardly to lower said opposite end, said handle beingdisengageable from said anvil and swingable outwardly therefrom on saidlever, to permit pipe blanks to be moved longitudinally over said anvil,clamping means arranged on each side of said anvil for clampingly andfrictionally urging the ends of the pipe blank into contactualengagement with the anvil, means for controlling said clamping means anda vertically adjustable platform mounted beneath said pipe blank forexerting an upward force on said pipe in opposition to said clampingmeans.

3. In a seam welding machine, a traokway, an electric welding unitmovable to and fro along said trackway, an anvil mounted beneath saidwelding unit for slidably receiving a cylindrical blank having a seam tobe welded with the seam presented to the welding unit, releasable meansfor supporting one end of said anvil to permit the loading and unloadingof cylindrical pipe blanks and pipe with respect to said anvil, alongitudinally disposed shaft mounted on each side of and above saidanvil, a series of closely spaced, clamping fingers pivotally mounted onand arranged the entire length of each shaft for clampingly engaging theends of the cylindrical blank between said anvil, pressure means forurging said clamping fingers into clamping engagement with said pipeblank a vertically adjustable platform beneath said pipe blank forexerting an upward pressure thereon, and manual control means forpivoting said shafts to permit the same to be adjusted independently ofsaid air pressure means.

4. In a disengageable support, means for supporting one end of an anvilin a seam welding machine, the combination comprising a lever on one endof said machine mounted to swing vertically in the longitudinal plane ofthe anvil, a handle member normally supporting said one end of the anvilin operative position, said member being ecoentrically pivotal in saidlever and swingable downwardly in a longitudinal plane to lower said endof the anvil, said lever and handle being swingable out of engagementwith said end of said anvil to permit pipe blanks to be loaded thereon.

5. The combination as defined in claim 4 in which a pivotal disk isprovided oiT-center in the free end of said lever, said disk beingprovided with an off-center opening, and said handle comprises aU-shaped member and a cross bar connecting the free ends thereof, saidcross-bar being accommodated in said oif-center opening in said disk,and rigid therein to pivot said disk when said handle member is swung.

6. In a seam welding machine, an electric welding unit movable along apathway, an anvil beneath said pathway for supporting a pipe blank withits seam presented to said welding unit, means on one end of saidmachine supporting one end of said anvil to allow limited pivotalswinging movement of said anvil in a vertical plane, a lever pivotallymounted on the opposite end of said machine to swing in a verticalplane, a handle member including a cross-bar eccentrically pivotal insaid lever, normally supporting the opposite end of said anvil, saidhandle memher being disengageable from said anvil to permit the loadingand unloading of pipe blanks on and from said anvil when said handle hasbeen swung downwardly to lower said opposite end of said anvil.

7. In a seam welding machine, an elongated frame structure, a trackwaysupported by said frame structure, an electric welding unit movableto-and-fro along said trackway, a longitudinally disposed anvil beneathsaid welding unit, eccentrically pivotal supporting means for releasablysupporting one end of said anvil on the frame structure to permitcylindrical blanks having a seam to be slid longitudinally over saidanvil, pivotally mounted clamping members arranged the entire length ofsaid anvil for engaging the edges of said cylindrical blanks to forcethem into intimate abutting relationship and to hold the same infrictional engagement with the anvil while the welding unit is movedto-and-fro to weld the seam, air pressure means mounted above thepivoted clamping members for urging them downwardly to operativeposition, gravity biased means for urging the clamping members up toinoperative position, a transverse shaft spanning one end of saidmachine, means mounted thereon connected with said clamping members andhandl means for actuating said shaft and adjusting said clamping membersindependently of said air pressure means.

HENRY B. TROMBLEY.

REFERENCES CITED The following references are of record in the I file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,612,317 Reed Dec. 28, 19261,668,783 Rupley May 8, 1928 1,782,316 Bobinoif Nov. 18, 1930 1,975,581Klein Oct. 2, 1934 1,983,930 Carlsen Dec. 11, 193 1 1,987,664 Brown Jan.15', 1935 1,997,296 Free Apr. 9, 1935 1,937,691 Lincoln Jan. 15, 1935FOREIGN PATENTS Number Country Date 381,527 Great Britain Oct. 6, 1932628,424 Germany Apr. 3, 1936

